The present invention relates to a coupling device comprising a female joint and a male joint capable of connecting/disconnecting the first and second fluid passages in first and second members.
The prior art put into practical use a coupling device comprising a first joint fitted on a first member such as a mold and work palette and a second joint fitted on a second member such as a mold fixture of a molding machine and a base member of a machining tool, when coupling/decoupling the first and second members in a predetermined positional relationship, for connecting/disconnecting the first and second fluid passages via the first and second joints in order to supply a fluid (cooling water, pressurized fluid, and so on) from one of the first and second fluid passages in the first and second members to the other while the first and second members are coupled (for example see the Patent Document 1).
The first and second joints consist of male and female joints, respectively, each having an open/close valve. The open/close valves of the male and female joints are closed while the male and female joints are separated. On the other hand, when the male and female joints are connected, the leading end portion of the male joint is inserted in the female joint and the leading end portion of the female joint is inserted in the leading end portion of the male joint so as to open the open/close valves of the male and female joints, whereby the first and second fluid passages are connected. In such a coupling device, the male and female joints generally protrude outward from the first and second members.
In the coupling device of the Patent Document 1, the male joint is fitted on a work pallet downward and the female joint is fitted on a base member of a machining tool upward. The male joint has a casing member fixed to the work pallet, a valve casing fitted in the casing member and protruding downward from the casing member, and a shaft-like valve body fitted in the valve casing movably in the advancing/retreating direction. The open/close valve is constituted by a valve seat and a valve portion provided at the lower ends of the valve casing and valve body.
A hydraulic cylinder for driving the female joint upward is provided to the base member of the machining tool. The female joint has a main body case fitted in the cylinder barrel of the hydraulic cylinder movably in the advancing/retreating direction and protruding upward from the cylinder barrel, a cylindrical member mounted in the main body case movably in the advancing/retreating direction, and a shaft-like valve body provided inside the cylindrical member and fixed to the body casing at the lower end. The open/close valve is constituted by a valve seat and a valve portion provided at the upper ends of the cylindrical member and valve body.
For connecting the separated male and female joints, the female joint is driven upward by the hydraulic cylinder while the male and female joints face each other one above the other. Here, first, the main body case, cylindrical member, and valve body of the female joint are moved upward together. The cylindrical member stops moving upward when its upper end abuts on the lower end of the valve casing of the male joint. Then, the main body case and valve body move upward together. Then, the valve body of the female joint is inserted in the valve casing of the male joint so that the valve body of the male joint is moved upward. The valve casing of the male joint is inserted in the main body case of the female joint so that the cylindrical member is moved downward in relation to the body casing and valve body in the female joint, whereby the open/close valves of the female and male joints are opened.    Patent Document 1: Japanese Laid-Open Patent Publication No. 2000-346266.